Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
When directly breastfeeding an infant is not feasible or desirable, a breastpump system can be used to express breast milk into a collection container. The collected breast milk may be used right away or may be stored for later use.
Breastpump systems typically include a breastshield to interface with the breast, a connector piece attached to a pump via tubing, and an outlet valve provided in the milk flow path to separate the pump's volume to which vacuum is applied (also known as the control volume or working volume) from the atmosphere as well as from the collection container downstream of the outlet valve. Separating the collection container from the control volume via the outlet valve generally serves to prevent undesirable vacuum level changes.
In the early days or weeks after delivery of an infant, the maternal milk supply is limited and includes colostrum. Colostrum production for some mothers may be as low as mere drops of the fluid per breast per pumping session, for example. For some mothers, for example, colostrum production may be less than 5 mL. Colostrum ingestion in the very earliest stages of post-partum life is considered to be highly valuable to the newborn infant. Colostrum is known to contain different content from mature breast milk. Colostrum contains antibodies that are major components of the immune system, anti-inflammatory agents, and growth factors that stimulate the development of the gut.
Colostrum also has unique physical properties as compared to mature breast milk, including higher viscosity and surface adhesion. Such properties often cause colostrum to become trapped by the various breastpump components, such as the connector and the valve or sticking directly to a surface, for example, reducing the amount of colostrum collected in the collection container. Because of the low volumes and the high nutritional and immunological value associated with colostrum production, reduced colostrum yield through the breastpump system due to trappings within the milk flow path may be more of an issue than a loss of mature milk for a more mature baby.
Additionally, during expression of mature milk, lower-fat foremilk is first expressed, followed by higher-fat hindmilk. If one wanted to observe the transition from foremilk to hindmilk, taking portions of expressed milk at discrete time points during the pumping process may be required. This type of portioning would be inconvenient given current systems. Such portions may be desired for analysis or for storage and later administration, such as administering higher-fat milk to babies that require high calorie feedings for example.